diff --git a/res/main.qml b/res/main.qml
index f23eee35..1f3a6063 100644
--- a/res/main.qml
+++ b/res/main.qml
@@ -61,6 +61,7 @@ Item {
         const kwinScriptingAPI = {
             workspace: workspace,
             options: options,
+            KWin: KWin
         };
 
         Bismuth.init(qmlObjects, kwinScriptingAPI);
diff --git a/src/config.ts b/src/config.ts
index 6de717d0..fff56d7f 100644
--- a/src/config.ts
+++ b/src/config.ts
@@ -31,7 +31,6 @@ import CascadeLayout from "./layouts/cascade_layout";
 
 import { ILayout } from "./ilayout";
 import { ILayoutClass } from "./ilayout";
-import { debug } from "./util/debug";
 
 export default interface IConfig {
   //#region Layout
@@ -83,6 +82,8 @@ export default interface IConfig {
   ignoreActivity: string[];
   ignoreScreen: number[];
   //#endregion
+
+  debugEnabled: boolean;
 }
 
 export class Config implements IConfig {
@@ -136,13 +137,19 @@ export class Config implements IConfig {
   public ignoreScreen: number[];
   //#endregion
 
-  constructor() {
+  public debugEnabled: boolean;
+
+  private kwinApi: KWin.Api;
+
+  constructor(kwinApi: KWin.Api) {
     function commaSeparate(str: string): string[] {
       if (!str || typeof str !== "string") return [];
       return str.split(",").map((part) => part.trim());
     }
 
-    DEBUG.enabled = DEBUG.enabled || KWin.readConfig("debug", false);
+    this.kwinApi = kwinApi;
+
+    this.debugEnabled = this.kwinApi.KWin.readConfig("debug", false);
 
     this.layoutOrder = [];
     this.layoutFactories = {};
@@ -159,62 +166,56 @@ export class Config implements IConfig {
         ["enableCascadeLayout", false, CascadeLayout], // TODO: add config
       ] as Array<[string, boolean, ILayoutClass]>
     ).forEach(([configKey, defaultValue, layoutClass]) => {
-      if (KWin.readConfig(configKey, defaultValue))
+      if (this.kwinApi.KWin.readConfig(configKey, defaultValue))
         this.layoutOrder.push(layoutClass.id);
       // TODO: Refactor this: config should not create factories. It is not its responsibility
       this.layoutFactories[layoutClass.id] = () => new layoutClass(this);
     });
 
-    this.maximizeSoleTile = KWin.readConfig("maximizeSoleTile", false);
-    this.monocleMaximize = KWin.readConfig("monocleMaximize", true);
-    this.monocleMinimizeRest = KWin.readConfig("monocleMinimizeRest", false);
+    this.maximizeSoleTile = this.kwinApi.KWin.readConfig("maximizeSoleTile", false);
+    this.monocleMaximize = this.kwinApi.KWin.readConfig("monocleMaximize", true);
+    this.monocleMinimizeRest = this.kwinApi.KWin.readConfig("monocleMinimizeRest", false);
 
-    this.adjustLayout = KWin.readConfig("adjustLayout", true);
-    this.adjustLayoutLive = KWin.readConfig("adjustLayoutLive", true);
-    this.keepFloatAbove = KWin.readConfig("keepFloatAbove", true);
-    this.noTileBorder = KWin.readConfig("noTileBorder", false);
+    this.adjustLayout = this.kwinApi.KWin.readConfig("adjustLayout", true);
+    this.adjustLayoutLive = this.kwinApi.KWin.readConfig("adjustLayoutLive", true);
+    this.keepFloatAbove = this.kwinApi.KWin.readConfig("keepFloatAbove", true);
+    this.noTileBorder = this.kwinApi.KWin.readConfig("noTileBorder", false);
 
     this.limitTileWidthRatio = 0;
-    if (KWin.readConfig("limitTileWidth", false))
-      this.limitTileWidthRatio = KWin.readConfig("limitTileWidthRatio", 1.6);
+    if (this.kwinApi.KWin.readConfig("limitTileWidth", false))
+      this.limitTileWidthRatio = this.kwinApi.KWin.readConfig("limitTileWidthRatio", 1.6);
 
-    this.screenGapBottom = KWin.readConfig("screenGapBottom", 0);
-    this.screenGapLeft = KWin.readConfig("screenGapLeft", 0);
-    this.screenGapRight = KWin.readConfig("screenGapRight", 0);
-    this.screenGapTop = KWin.readConfig("screenGapTop", 0);
-    this.tileLayoutGap = KWin.readConfig("tileLayoutGap", 0);
+    this.screenGapBottom = this.kwinApi.KWin.readConfig("screenGapBottom", 0);
+    this.screenGapLeft = this.kwinApi.KWin.readConfig("screenGapLeft", 0);
+    this.screenGapRight = this.kwinApi.KWin.readConfig("screenGapRight", 0);
+    this.screenGapTop = this.kwinApi.KWin.readConfig("screenGapTop", 0);
+    this.tileLayoutGap = this.kwinApi.KWin.readConfig("tileLayoutGap", 0);
 
-    const directionalKeyDwm = KWin.readConfig("directionalKeyDwm", true);
-    const directionalKeyFocus = KWin.readConfig("directionalKeyFocus", false);
+    const directionalKeyDwm = this.kwinApi.KWin.readConfig("directionalKeyDwm", true);
+    const directionalKeyFocus = this.kwinApi.KWin.readConfig("directionalKeyFocus", false);
     this.directionalKeyMode = directionalKeyDwm ? "dwm" : "focus";
-    this.newWindowAsMaster = KWin.readConfig("newWindowAsMaster", false);
+    this.newWindowAsMaster = this.kwinApi.KWin.readConfig("newWindowAsMaster", false);
 
-    this.layoutPerActivity = KWin.readConfig("layoutPerActivity", true);
-    this.layoutPerDesktop = KWin.readConfig("layoutPerDesktop", true);
-    this.floatUtility = KWin.readConfig("floatUtility", true);
-    this.preventMinimize = KWin.readConfig("preventMinimize", false);
-    this.preventProtrusion = KWin.readConfig("preventProtrusion", true);
-    this.pollMouseXdotool = KWin.readConfig("pollMouseXdotool", false);
+    this.layoutPerActivity = this.kwinApi.KWin.readConfig("layoutPerActivity", true);
+    this.layoutPerDesktop = this.kwinApi.KWin.readConfig("layoutPerDesktop", true);
+    this.floatUtility = this.kwinApi.KWin.readConfig("floatUtility", true);
+    this.preventMinimize = this.kwinApi.KWin.readConfig("preventMinimize", false);
+    this.preventProtrusion = this.kwinApi.KWin.readConfig("preventProtrusion", true);
+    this.pollMouseXdotool = this.kwinApi.KWin.readConfig("pollMouseXdotool", false);
 
-    this.floatingClass = commaSeparate(KWin.readConfig("floatingClass", ""));
-    this.floatingTitle = commaSeparate(KWin.readConfig("floatingTitle", ""));
-    this.ignoreActivity = commaSeparate(KWin.readConfig("ignoreActivity", ""));
+    this.floatingClass = commaSeparate(this.kwinApi.KWin.readConfig("floatingClass", ""));
+    this.floatingTitle = commaSeparate(this.kwinApi.KWin.readConfig("floatingTitle", ""));
+    this.ignoreActivity = commaSeparate(this.kwinApi.KWin.readConfig("ignoreActivity", ""));
     this.ignoreClass = commaSeparate(
-      KWin.readConfig("ignoreClass", "krunner,yakuake,spectacle,kded5")
+      this.kwinApi.KWin.readConfig("ignoreClass", "krunner,yakuake,spectacle,kded5")
     );
-    this.ignoreRole = commaSeparate(KWin.readConfig("ignoreRole", "quake"));
+    this.ignoreRole = commaSeparate(this.kwinApi.KWin.readConfig("ignoreRole", "quake"));
 
-    this.ignoreScreen = commaSeparate(KWin.readConfig("ignoreScreen", "")).map(
+    this.ignoreScreen = commaSeparate(this.kwinApi.KWin.readConfig("ignoreScreen", "")).map(
       (str) => parseInt(str, 10)
     );
-    this.ignoreTitle = commaSeparate(KWin.readConfig("ignoreTitle", ""));
+    this.ignoreTitle = commaSeparate(this.kwinApi.KWin.readConfig("ignoreTitle", ""));
 
-    if (this.preventMinimize && this.monocleMinimizeRest) {
-      debug(
-        () => "preventMinimize is disabled because of monocleMinimizeRest."
-      );
-      this.preventMinimize = false;
-    }
   }
 
   public toString(): string {
diff --git a/src/driver/kwin/kwin_config.ts b/src/driver/kwin/kwin_config.ts
deleted file mode 100644
index 7c3bca7d..00000000
--- a/src/driver/kwin/kwin_config.ts
+++ /dev/null
@@ -1,19 +0,0 @@
-// Copyright (c) 2018-2019 Eon S. Jeon <esjeon@hyunmu.am>
-//
-// Permission is hereby granted, free of charge, to any person obtaining a
-// copy of this software and associated documentation files (the "Software"),
-// to deal in the Software without restriction, including without limitation
-// the rights to use, copy, modify, merge, publish, distribute, sublicense,
-// and/or sell copies of the Software, and to permit persons to whom the
-// Software is furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in
-// all copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
-// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
-// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
-// DEALINGS IN THE SOFTWARE.
diff --git a/src/driver/kwin/kwin_driver.ts b/src/driver/kwin/kwin_driver.ts
index 32f6dd3d..e48ed0d7 100644
--- a/src/driver/kwin/kwin_driver.ts
+++ b/src/driver/kwin/kwin_driver.ts
@@ -40,9 +40,8 @@ import { KWinSetTimeout } from "./kwin_set_timeout";
 import { ILayoutClass } from "../../ilayout";
 import { WindowState } from "../../engine/window";
 import WrapperMap from "../../util/wrappermap";
-import { debug, debugObj } from "../../util/debug";
 import IConfig, { Config } from "../../config";
-// import { workspace } from "../../extern/global";
+import Debug from "../../util/debug";
 
 /**
  * Abstracts KDE implementation specific details.
@@ -123,24 +122,38 @@ export default class KWinDriver implements IDriverContext {
   private kwinApi: KWin.Api;
 
   private config: IConfig;
+  private debug: Debug;
 
-  constructor(qmlObjects: Bismuth.Qml.Main, kwinScriptingApi: KWin.Api, config?: IConfig) {
+  /**
+   * @param qmlObjects objects from QML gui. Required for the interaction with QML, as we cannot access globals.
+   * @param kwinApi KWin scripting API. Required for interaction with KWin, as we cannot access globals.
+   * @param config Bismuth configuration. If none is provided, the configuration is read from KConfig (in most cases from config file).
+   */
+  constructor(qmlObjects: Bismuth.Qml.Main, kwinApi: KWin.Api, config?: IConfig) {
     if (config) {
       this.config = config;
     } else {
-      this.config = new Config();
+      this.config = new Config(kwinApi);
+    }
+    this.debug = new Debug(this.config);
+
+    if (this.config.preventMinimize && this.config.monocleMinimizeRest) {
+      this.debug.debug(
+        () => "preventMinimize is disabled because of monocleMinimizeRest."
+      );
+      this.config.preventMinimize = false;
     }
 
-    this.engine = new TilingEngine(this.config);
-    this.control = new TilingController(this.engine, this.config);
+    this.engine = new TilingEngine(this.config, this.debug);
+    this.control = new TilingController(this.engine, this.config, this.debug);
     this.windowMap = new WrapperMap(
       (client: KWin.Client) => KWinWindow.generateID(client),
-      (client: KWin.Client) => new Window(new KWinWindow(client, this.qml, this.kwinApi, this.config), this.config)
+      (client: KWin.Client) => new Window(new KWinWindow(client, this.qml, this.kwinApi, this.config, this.debug), this.config, this.debug)
     );
     this.entered = false;
-    this.mousePoller = new KWinMousePoller(qmlObjects, this.config);
+    this.mousePoller = new KWinMousePoller(qmlObjects, this.config, this.debug);
     this.qml = qmlObjects;
-    this.kwinApi = kwinScriptingApi;
+    this.kwinApi = kwinApi;
   }
 
   /**
@@ -149,12 +162,7 @@ export default class KWinDriver implements IDriverContext {
   public main() {
     console.log("Initiating systems!");
 
-    // DEBUG = {
-    //   enabled: false,
-    //   started: new Date().getTime(),
-    // };
-
-    // debug(() => "Config: " + this.config);
+    this.debug.debug(() => "Config: " + this.config);
 
     this.bindEvents();
     this.bindShortcut();
@@ -172,7 +180,7 @@ export default class KWinDriver implements IDriverContext {
 
   //#region implement methods of IDriverContext`
   public setTimeout(func: () => void, timeout: number) {
-    KWinSetTimeout(() => this.enter(func), timeout, this.qml.scriptRoot);
+    KWinSetTimeout(() => this.enter(func), timeout, this.qml.scriptRoot, this.debug);
   }
 
   public showNotification(text: string) {
@@ -181,8 +189,8 @@ export default class KWinDriver implements IDriverContext {
   //#endregion
 
   private bindShortcut() {
-    if (!KWin.registerShortcut) {
-      debug(
+    if (!this.kwinApi.KWin.registerShortcut) {
+      this.debug.debug(
         () => "KWin.registerShortcut doesn't exist. Omitting shortcut binding."
       );
       return;
@@ -191,7 +199,7 @@ export default class KWinDriver implements IDriverContext {
     const bind = (seq: string, title: string, input: Shortcut) => {
       title = "Krohnkite: " + title;
       seq = "Meta+" + seq;
-      KWin.registerShortcut(title, "", seq, () => {
+      this.kwinApi.KWin.registerShortcut(title, "", seq, () => {
         this.enter(() => this.control.onShortcut(this, input));
       });
     };
@@ -232,7 +240,7 @@ export default class KWinDriver implements IDriverContext {
     ) => {
       title = "Krohnkite: " + title + " Layout";
       seq = seq !== "" ? "Meta+" + seq : "";
-      KWin.registerShortcut(title, "", seq, () => {
+      this.kwinApi.KWin.registerShortcut(title, "", seq, () => {
         this.enter(() =>
           this.control.onShortcut(this, Shortcut.SetLayout, layoutClass.id)
         );
@@ -268,7 +276,7 @@ export default class KWinDriver implements IDriverContext {
    * Run the given function in a protected(?) context to prevent nested event
    * handling.
    *
-   * KWin emits signals as soons as window states are changed, even when
+   * KWin emits signals as soon as window states are changed, even when
    * those states are modified by the script. This causes multiple re-entry
    * during event handling, resulting in performance degradation and harder
    * debugging.
@@ -282,7 +290,7 @@ export default class KWinDriver implements IDriverContext {
     } catch (e) {
       // TODO: investigate why this line prevents compiling
       // debug(() => "Error raised from line " + e.lineNumber);
-      debug(() => e);
+      this.debug.debug(() => e);
     } finally {
       this.entered = false;
     }
@@ -397,7 +405,7 @@ export default class KWinDriver implements IDriverContext {
     let resizing = false;
 
     this.connect(client.moveResizedChanged, () => {
-      debugObj(() => [
+      this.debug.debugObj(() => [
         "moveResizedChanged",
         { window, move: client.move, resize: client.resize },
       ]);
diff --git a/src/driver/kwin/kwin_mouse_poller.ts b/src/driver/kwin/kwin_mouse_poller.ts
index 26c0efcd..3769284b 100644
--- a/src/driver/kwin/kwin_mouse_poller.ts
+++ b/src/driver/kwin/kwin_mouse_poller.ts
@@ -19,6 +19,7 @@
 // DEALINGS IN THE SOFTWARE.
 
 import IConfig from "../../config";
+import Debug from "../../util/debug";
 import { KWinSetTimeout } from "./kwin_set_timeout";
 
 export default class KWinMousePoller {
@@ -39,7 +40,7 @@ export default class KWinMousePoller {
   private qml: Bismuth.Qml.Main;
   private config: IConfig;
 
-  constructor(qml: Bismuth.Qml.Main, config: IConfig) {
+  constructor(qml: Bismuth.Qml.Main, config: IConfig, debug: Debug) {
     this.startCount = 0;
     this.cmdResult = null;
     this.qml = qml;
@@ -56,7 +57,7 @@ export default class KWinMousePoller {
 
       KWinSetTimeout(() => {
         if (this.started) qml.mousePoller.connectSource(KWinMousePoller.COMMAND);
-      }, KWinMousePoller.INTERVAL, this.qml.scriptRoot);
+      }, KWinMousePoller.INTERVAL, this.qml.scriptRoot, debug);
     });
   }
 
diff --git a/src/driver/kwin/kwin_set_timeout.ts b/src/driver/kwin/kwin_set_timeout.ts
index a793a256..bf4b07f8 100644
--- a/src/driver/kwin/kwin_set_timeout.ts
+++ b/src/driver/kwin/kwin_set_timeout.ts
@@ -18,7 +18,7 @@
 // FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 // DEALINGS IN THE SOFTWARE.
 
-import { debugObj } from "../../util/debug";
+import Debug from "../../util/debug";
 
 export default class KWinTimerPool {
   public static readonly instance = new KWinTimerPool();
@@ -31,10 +31,10 @@ export default class KWinTimerPool {
     this.numTimers = 0;
   }
 
-  public setTimeout(func: () => void, timeout: number, scriptRoot: object) {
+  public setTimeout(func: () => void, timeout: number, scriptRoot: object, debug: Debug) {
     if (this.timers.length === 0) {
       this.numTimers++;
-      debugObj(() => ["setTimeout/newTimer", { numTimers: this.numTimers }]);
+      debug.debugObj(() => ["setTimeout/newTimer", { numTimers: this.numTimers }]);
     }
 
     const timer: QQmlTimer =
@@ -62,6 +62,6 @@ export default class KWinTimerPool {
   }
 }
 
-export function KWinSetTimeout(func: () => void, timeout: number, scriptRoot: object) {
-  KWinTimerPool.instance.setTimeout(func, timeout, scriptRoot);
+export function KWinSetTimeout(func: () => void, timeout: number, scriptRoot: object, debug: Debug) {
+  KWinTimerPool.instance.setTimeout(func, timeout, scriptRoot, debug);
 }
diff --git a/src/driver/kwin/kwin_surface.ts b/src/driver/kwin/kwin_surface.ts
index f8d72502..42590a4b 100644
--- a/src/driver/kwin/kwin_surface.ts
+++ b/src/driver/kwin/kwin_surface.ts
@@ -55,7 +55,7 @@ export default class KWinSurface implements ISurface {
       this.config.ignoreActivity.indexOf(activityName) >= 0 ||
       this.config.ignoreScreen.indexOf(screen) >= 0;
     this.workingArea = toRect(
-      this.kwinApi.workspace.clientArea(KWin.PlacementArea, screen, desktop)
+      this.kwinApi.workspace.clientArea(this.kwinApi.KWin.PlacementArea, screen, desktop)
     );
 
     this.screen = screen;
diff --git a/src/driver/kwin/kwin_window.ts b/src/driver/kwin/kwin_window.ts
index 38fe169a..fbc4f5fb 100644
--- a/src/driver/kwin/kwin_window.ts
+++ b/src/driver/kwin/kwin_window.ts
@@ -24,8 +24,8 @@ import KWinSurface from "./kwin_surface";
 import Rect from "../../util/rect";
 import { toQRect, toRect } from "../../util/kwinutil";
 import { clip, matchWords } from "../../util/func";
-import { debugObj } from "../../util/debug";
 import IConfig from "../../config";
+import Debug from "../../util/debug";
 
 export default class KWinWindow implements IDriverWindow {
   public static generateID(client: KWin.Client) {
@@ -101,8 +101,9 @@ export default class KWinWindow implements IDriverWindow {
   private qml: Bismuth.Qml.Main;
   private kwinApi: KWin.Api;
   private config: IConfig;
+  private debug: Debug;
 
-  constructor(client: KWin.Client, qml: Bismuth.Qml.Main, kwinApi: KWin.Api, config: IConfig) {
+  constructor(client: KWin.Client, qml: Bismuth.Qml.Main, kwinApi: KWin.Api, config: IConfig, debug: Debug) {
     this.client = client;
     this.id = KWinWindow.generateID(client);
     this.maximized = false;
@@ -111,10 +112,11 @@ export default class KWinWindow implements IDriverWindow {
     this.qml = qml;
     this.kwinApi = kwinApi;
     this.config = config;
+    this.debug = debug;
   }
 
   public commit(geometry?: Rect, noBorder?: boolean, keepAbove?: boolean) {
-    debugObj(() => ["KWinWindow#commit", { geometry, noBorder, keepAbove }]);
+    this.debug.debugObj(() => ["KWinWindow#commit", { geometry, noBorder, keepAbove }]);
 
     if (this.client.move || this.client.resize) return;
 
@@ -145,7 +147,7 @@ export default class KWinWindow implements IDriverWindow {
       if (this.config.preventProtrusion) {
         const area = toRect(
           this.kwinApi.workspace.clientArea(
-            KWin.PlacementArea,
+            this.kwinApi.KWin.PlacementArea,
             this.client.screen,
             this.kwinApi.workspace.currentDesktop
           )
diff --git a/src/engine/tiling_controler.ts b/src/engine/tiling_controler.ts
index c68a4183..1e3bd9ae 100644
--- a/src/engine/tiling_controler.ts
+++ b/src/engine/tiling_controler.ts
@@ -23,8 +23,8 @@ import IDriverContext from "../idriver_context";
 import Window from "./window";
 import { WindowState } from "./window";
 import { Shortcut } from "../shortcut";
-import { debugObj } from "../util/debug";
 import IConfig from "../config";
+import Debug from "../util/debug";
 
 /**
  * TilingController translates events to actions, implementing high-level
@@ -35,24 +35,26 @@ import IConfig from "../config";
 export default class TilingController {
   private engine: TilingEngine;
   private config: IConfig;
+  private debug: Debug;
 
-  public constructor(engine: TilingEngine, config: IConfig) {
+  public constructor(engine: TilingEngine, config: IConfig, debug: Debug) {
     this.engine = engine;
     this.config = config;
+    this.debug = debug;
   }
 
   public onSurfaceUpdate(ctx: IDriverContext, comment: string): void {
-    debugObj(() => ["onSurfaceUpdate", { comment }]);
+    this.debug.debugObj(() => ["onSurfaceUpdate", { comment }]);
     this.engine.arrange(ctx);
   }
 
   public onCurrentSurfaceChanged(ctx: IDriverContext): void {
-    debugObj(() => ["onCurrentSurfaceChanged", { srf: ctx.currentSurface }]);
+    this.debug.debugObj(() => ["onCurrentSurfaceChanged", { srf: ctx.currentSurface }]);
     this.engine.arrange(ctx);
   }
 
   public onWindowAdded(ctx: IDriverContext, window: Window): void {
-    debugObj(() => ["onWindowAdded", { window }]);
+    this.debug.debugObj(() => ["onWindowAdded", { window }]);
     this.engine.manage(window);
 
     /* move window to next surface if the current surface is "full" */
@@ -74,7 +76,7 @@ export default class TilingController {
   }
 
   public onWindowRemoved(ctx: IDriverContext, window: Window): void {
-    debugObj(() => ["onWindowRemoved", { window }]);
+    this.debug.debugObj(() => ["onWindowRemoved", { window }]);
     this.engine.unmanage(window);
     this.engine.arrange(ctx);
   }
@@ -88,7 +90,7 @@ export default class TilingController {
   }
 
   public onWindowMoveOver(ctx: IDriverContext, window: Window): void {
-    debugObj(() => ["onWindowMoveOver", { window }]);
+    this.debug.debugObj(() => ["onWindowMoveOver", { window }]);
 
     /* swap window by dragging */
     if (window.state === WindowState.Tiled) {
@@ -129,7 +131,7 @@ export default class TilingController {
   }
 
   public onWindowResize(ctx: IDriverContext, window: Window): void {
-    debugObj(() => ["onWindowResize", { window }]);
+    this.debug.debugObj(() => ["onWindowResize", { window }]);
     if (this.config.adjustLayout && this.config.adjustLayoutLive) {
       if (window.state === WindowState.Tiled) {
         this.engine.adjustLayout(window);
@@ -139,7 +141,7 @@ export default class TilingController {
   }
 
   public onWindowResizeOver(ctx: IDriverContext, window: Window): void {
-    debugObj(() => ["onWindowResizeOver", { window }]);
+    this.debug.debugObj(() => ["onWindowResizeOver", { window }]);
     if (this.config.adjustLayout && window.tiled) {
       this.engine.adjustLayout(window);
       this.engine.arrange(ctx);
@@ -155,7 +157,7 @@ export default class TilingController {
   }
 
   public onWindowGeometryChanged(ctx: IDriverContext, window: Window): void {
-    debugObj(() => ["onWindowGeometryChanged", { window }]);
+    this.debug.debugObj(() => ["onWindowGeometryChanged", { window }]);
     this.engine.enforceSize(ctx, window);
   }
 
@@ -167,7 +169,7 @@ export default class TilingController {
     comment?: string
   ): void {
     if (window) {
-      debugObj(() => ["onWindowChanged", { window, comment }]);
+      this.debug.debugObj(() => ["onWindowChanged", { window, comment }]);
 
       if (comment === "unminimized") ctx.currentWindow = window;
 
diff --git a/src/engine/tiling_engine.ts b/src/engine/tiling_engine.ts
index b642be66..a93dafcc 100644
--- a/src/engine/tiling_engine.ts
+++ b/src/engine/tiling_engine.ts
@@ -30,9 +30,9 @@ import { Shortcut } from "../shortcut";
 import { WindowState } from "./window";
 import Rect from "../util/rect";
 import RectDelta from "../util/rectdelta";
-import { debug, debugObj } from "../util/debug";
 import { overlap, wrapIndex } from "../util/func";
 import IConfig from "../config";
+import Debug from "../util/debug";
 
 export type Direction = "up" | "down" | "left" | "right";
 
@@ -44,9 +44,11 @@ export default class TilingEngine {
   public windows: WindowStore;
 
   private config: IConfig;
+  private debug: Debug;
 
-  constructor(config: IConfig) {
+  constructor(config: IConfig, debug: Debug) {
     this.config = config;
+    this.debug = debug;
     this.layouts = new LayoutStore(this.config);
     this.windows = new WindowStore();
   }
@@ -199,7 +201,7 @@ export default class TilingEngine {
    * Arrange tiles on all screens.
    */
   public arrange(ctx: IDriverContext) {
-    debug(() => "arrange");
+    this.debug.debug(() => "arrange");
     ctx.screens.forEach((srf: ISurface) => {
       this.arrangeScreen(ctx, srf);
     });
@@ -225,7 +227,7 @@ export default class TilingEngine {
       );
 
     const visibles = this.windows.getVisibleWindows(srf);
-    debugObj(() => [
+    this.debug.debugObj(() => [
       "arrangeScreen",
       {
         layout,
@@ -266,7 +268,7 @@ export default class TilingEngine {
     }
 
     visibles.forEach((window) => window.commit());
-    debugObj(() => ["arrangeScreen/finished", { srf }]);
+    this.debug.debugObj(() => ["arrangeScreen/finished", { srf }]);
   }
 
   /**
diff --git a/src/engine/window.ts b/src/engine/window.ts
index eead0a24..b87696b0 100644
--- a/src/engine/window.ts
+++ b/src/engine/window.ts
@@ -21,7 +21,7 @@
 import IConfig from "../config";
 import IDriverWindow from "../idriver_window";
 import ISurface from "../isurface";
-import { debugObj } from "../util/debug";
+import Debug from "../util/debug";
 import Rect from "../util/rect";
 import RectDelta from "../util/rectdelta";
 
@@ -154,9 +154,11 @@ export default class Window {
   private weightMap: { [key: string]: number };
 
   private config: IConfig;
+  private debug: Debug;
 
-  constructor(window: IDriverWindow, config: IConfig) {
+  constructor(window: IDriverWindow, config: IConfig, debug: Debug) {
     this.config = config;
+    this.debug = debug;
 
     this.id = window.id;
     this.window = window;
@@ -172,7 +174,7 @@ export default class Window {
 
   public commit() {
     const state = this.state;
-    debugObj(() => ["Window#commit", { state: WindowState[state] }]);
+    this.debug.debugObj(() => ["Window#commit", { state: WindowState[state] }]);
     switch (state) {
       case WindowState.NativeMaximized:
         this.window.commit(undefined, undefined, false);
diff --git a/src/extern/kwin.d.ts b/src/extern/kwin.d.ts
index 8a7b8a82..bf592065 100644
--- a/src/extern/kwin.d.ts
+++ b/src/extern/kwin.d.ts
@@ -1,4 +1,5 @@
 // Copyright (c) 2018-2019 Eon S. Jeon <esjeon@hyunmu.am>
+// Copyright (c) 2021 Mikhail Zolotukhin <mail@genda.life>
 //
 // Permission is hereby granted, free of charge, to any person obtaining a
 // copy of this software and associated documentation files (the "Software"),
@@ -20,23 +21,19 @@
 
 // API Reference: https://develop.kde.org/docs/plasma/kwin/api/
 
+// TODO: Register the rest of the API
 declare namespace KWin {
   interface Api {
     workspace: KWin.WorkspaceWrapper;
     options: KWin.Options;
+    KWin: KWin.KWin;
   }
 
-  /* enum ClientAreaOption */
-  var PlacementArea: number;
-
-  function readConfig(key: string, defaultValue?: any): any;
-
-  function registerShortcut(
-    title: string,
-    text: string,
-    keySequence: string,
-    callback: any
-  ): boolean;
+  interface KWin {
+    readConfig(key: string, defaultValue?: any): any;
+    registerShortcut(title: string, text: string, keySequence: string, callback: any): boolean;
+    PlacementArea: number;
+  }
 
   interface WorkspaceWrapper {
     /* read-only */
diff --git a/src/index.ts b/src/index.ts
index b3efb0eb..72b18db4 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -18,9 +18,13 @@
 // FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 // DEALINGS IN THE SOFTWARE.
 
-
 import KWinDriver from "./driver/kwin/kwin_driver"
 
+/**
+ * Script entry-point from QML side.
+ * @param qmlObjects objects from QML gui. Required for the interaction with QML, as we cannot access globals.
+ * @param kwinApi KWin scripting API. Required for interaction with KWin, as we cannot access globals.
+ */
 export function init(qmlObjects: Bismuth.Qml.Main, kwinScriptingApi: KWin.Api) {
   const driver = new KWinDriver(qmlObjects, kwinScriptingApi)
   driver.main()
diff --git a/src/util/debug.ts b/src/util/debug.ts
index e7099c9d..5940e703 100644
--- a/src/util/debug.ts
+++ b/src/util/debug.ts
@@ -1,4 +1,5 @@
 // Copyright (c) 2018-2019 Eon S. Jeon <esjeon@hyunmu.am>
+// Copyright (c) 2021 Mikhail Zolotukhin <mail@genda.life>
 //
 // Permission is hereby granted, free of charge, to any person obtaining a
 // copy of this software and associated documentation files (the "Software"),
@@ -18,29 +19,32 @@
 // FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 // DEALINGS IN THE SOFTWARE.
 
-declare global {
-  var DEBUG: any
-}
+import IConfig from "../config";
 
-var DEBUG = {
-  enabled: false,
-  started: new Date().getTime(),
-};
+export default class Debug {
+  private enabled: boolean;
+  private started: number;
 
-export function debug(f: () => any) {
-  if (DEBUG.enabled) {
-    const timestamp = (new Date().getTime() - DEBUG.started) / 1000;
-    console.log("[" + timestamp + "]", f()); // tslint:disable-line:no-console
-  }
-}
-
-export function debugObj(f: () => [string, any]) {
-  if (DEBUG.enabled) {
-    const timestamp = (new Date().getTime() - DEBUG.started) / 1000;
-    const [name, obj] = f();
-    const buf = [];
-    for (const i in obj) buf.push(i + "=" + obj[i]);
-
-    console.log("[" + timestamp + "]", name + ": " + buf.join(" ")); // tslint:disable-line:no-console
+  constructor(config: IConfig) {
+    this.enabled = config.debugEnabled;
+    this.started = new Date().getTime();
+  }
+
+  public debug(f: () => any): void {
+    if (this.enabled) {
+      const timestamp = (new Date().getTime() - this.started) / 1000;
+      console.log("[" + timestamp + "]", f()); // tslint:disable-line:no-console
+    }
+  }
+
+  public debugObj(f: () => [string, any]): void {
+    if (this.enabled) {
+      const timestamp = (new Date().getTime() - this.started) / 1000;
+      const [name, obj] = f();
+      const buf = [];
+      for (const i in obj) buf.push(i + "=" + obj[i]);
+
+      console.log("[" + timestamp + "]", name + ": " + buf.join(" ")); // tslint:disable-line:no-console
+    }
   }
 }